Fütterungsversuche an Schweinen mit freien Fettsäuren hydrierter Seetieröle in den Rationen

Feeding Studies on Pigs with Free Fatty Acid Fractions of Hydrogenated Marine Oils Feeding studies with castrated boars that were given 0, 4, 8 and 12% of hydrogenated marine oil fatty acids resulted in constant coefficients of digestion, for which no explanation has been found so far. Addition of mono- and diglycerides did not improve the absorption. Two experiments with slaughter pigs did not show any negative effect on the carcass quality with Increasing levels of fatty acids up to 12%. A higher content of trans-fatty acids in the back fat was observed with increasing proportions of the free fatty acids fed. The content of unsaturated fatty acids in the back fat was very little affected by the hydrogenated marine oil fatty acids in the diet.     

Produkte der Dimerisierung ungesättigter Fettsäuren V: Die Aromatenfraktion dimerer Fettsäuren

Products of Dimerisation of Unsaturated Fatty Acids V: The Aromatic Fraction of Dimeric Acids The aromatic fraction of dimeric fatty acid esters can be separated according to a decreasing grade of unsaturation by HPLC using an UV-recorder. Hydrogenation experiments of the collected fractions allowed the determination of the number of rings. If the aromatic fraction are oxidized with KMnO₄ using a phase-transfer catalyst benzene 1,2,4- and 1,3,5-tri-, 1,2,4,5-and 1,2,3,5-tetra- and the pentacarboxylic acid were obtained as main products. Consequently we have to conclude that the catalyst causes intramolecular extensive migration of alkyl chains. Finally 2,3-dihydrobenzofurantetracarboxylic acids with different position of the carboxylic groups were detected in the mixture of oxidation products.     

Zur Analytik von Kondensationsprodukten aus Fettsäuren bzw. deren Methylestern mit Aminoethylethanolamin

Analysis of Condensation Products of Fatty Acids or Their Methyl Esters with Aminoethylethanolamine Imidazoline derivatives, formed by the aforesaid condensation, react with sodiummonochloroacetate to yields products having interesting properties, whose structures are now believed to be of the imidazolinium-betaine-type. This can not be the case, since the latter would exhibit a UV-absorption that is not found in the commercial products. Therefore, the composition of the starting product, i. e. the imidazolines, and their products of hydrolysis was investigated. For this purpose, the quantitative oxidation of the hydroxyethylaminoethyl group with periodate for the direct determination of this secondary basic nitrogen was successfully used for the first time. It was found that the imidazolines derived from fatty acid and amine as well as their hydrolysis products are simple mixtures, whereas a product prepared from methyl esters according to USP. 3 941 817 was found to be composed of several components in similar proportions.     

Produkte der Dimerisierung ungesättigter Fettsäuren VI: Untersuchungen zur Kinetik der Bildung dimerer Fettsäuren

Products of Dimerisation of Unsaturated Fatty Acids VI: Kinetic Studies about the Formation of Dimeric Fatty Acids During the dimerisation reaction of a mixture of 60% oleic acid and 40% linoleic acid samples were collected in time intervals. The samples were converted into their dimethylates by diazomethane and separated by thin layer chromatography in one fraction of monomers and one of dimers. The monomeric fractions were further separated by GC, the dimeric fractions by HPLC. First linoleic acid reacts, either by cyclisation or by attacking another molecule of linoleic acid. Thus linoleic acid has already disappeared nearly completely at the end of the heating up period (after 60 min). The less linoleic acid is present, the more molecules of linoleic acid react with oleic acid molecules. The primary cyclic dimerisation products are slowly converted to aromatic compounds as well as cyclohexane derivatives. The oleic acid is transformed already in the heating up period into its isomer, elaidic acid and isomers thereof with double bonds in other positions of the chain. These products are converted slowly partly to stearic acid, partly to isostearic acids. Dimeric compounds of MW 592 (methylates) are produced as well by reaction of 2 molecules of oleic acid. They are slowly converted to open chain dimeric acids of MW 594 (methylates).     

Untersuchungen über die Struktur dimerer Fettsäuren I: Struktur dimerer Ölsäure-methylester

Investigation on the Structure of Dimeric Fatty Acids, Part I: Structure of Dimeric Methyl Oleates Monoenoic as well as dienoic dimers were synthesized from methyl oleate and compared thin-layer chromatographically with a mixture of dimers obtained from thermally treated methyl oleate. By this means it was made to appear very likely that the unsaturated components of the mixture of dimers comprise monoenoic and dienoic dimers. The mixture contained, beside 30% saturated dimers, 30% dienoic and 40% monoenoic dimers. By analysis with mass- and NMR-spectra an unequivocal characterization of the ring system in saturated dimers was not possible. The mechanism of the dimerisation is discussed.     

Untersuchungen über die Struktur dimerer Fettsäuren IV: Struktur dimerer 9c,12c-Octadecadiensäure-methylester

Investigations on the Structure of Dimeric Fatty Acids, Part IV: Structure of Dimeric Methyl-9^c,12^c-octadecadienoates After 65 hrs. of heating methyl-9^c,12^c-linoleate at 280°C under argon, dimers in 24% yield could be isolated, which can be hydrogenated to completeness. Mass spectrometry of the mixture of dimers and those of their hydrogenated products showed that the dimers comprise of saturated tricyclic, monounsaturated bicyclic, diunsaturated monocyclic and triunsaturated acyclic dimers, all having the mol. weight 588, and dehydrodimers having mol. weight 586. Acyclic dehydrodimers with four double bonds could not be detected. Mass spectrometry of the conversion products of the dimers with monoperphthalic acid showed that the dehydrodimers occur predominantly as bicyclic and tricyclic compounds with two double bonds and one double bond respectively. Diels-Alder dimers with tetrasubstituted cyclohexene structure are not formed in the thermal dimerisation of methyl-9,12-linoleate under aforesaid conditions. The possible path of formation of the dimers via radical intermediates is discussed.     

Produkte der Dimerisierung ungesättigter Fettsäuren III: Trennung dimerer Fettsäuren mittels GC und HPLC — Nachweis aliphatischer und verzweigter Dicarbonsäuren

Products of the Dimerisation of Unsaturated Fatty Acids III: Separation of Dimeric Fatty Acids with the Aid of GC and HPLC — Identification of Branched Aliphatic Dicarboxylic Acids From dimers produced by dimerisation of pure oleic acid we obtain by freezing small amounts of compounds, which can be separated further by GC. The separated compounds are isomers with a molecular weight of 594. They are saturated branched aliphatic dicarboxylic acid esters. They are obviously produced by en-reaction followed by hydrogenation. A much more effective separation than by GC is possible by HPLC, using a detector based on light scattering. Thus the dimeric fatty esters can be separated into four fractions: the first fraction consists of aromatics, the second obviously of alicyclic and unsaturated dicarboxylic acids, the third and fourth consist of aliphatic dicarboxylic acid esters of MW 594. Fatty acids obtained by dimerisation of a starting material rich in linoleic acid contain large amounts of aromatic compounds, those which are obtained by dimerisation of starting material rich in oleic acid contain rather high amounts of aliphatic dicarboxylic acids and practically no aromatic compounds.     

Bestimmung aromatischer Fettsäuren in hydrierten cyclischen Fettsäuren

Determination of Aromatic Fatty Acids in Hydrogenated Cyclic Fatty Acids Small amounts of aromatic fatty acids, besides hydrogenated cyclic fatty acids, in an urea non-adduct from hydrogenated fatty acids can not be determined by gas chromatography. A direct determination by UV-spectroscopy is also inaccurate, since the strong end absorption of the carbonyl group makes an evaluation of the aromatic band in the range of 260 to 275 nm difficult. After reducing the acids or esters with lithium aluminium hydride to the corresponding alcohols, a proper quantitative determination of aromatic fatty acids can be carried out even at low concentrations of the latter.     

Fütterungsversuche mit dimeren Triglyceriden aus Sojaölraffinat

Feeding Experiments with Dimeric Triglycerides Isolated from Refined Soya Bean Oil At pilot plant scale a fraction containing 20% of dimeric triglycerides was isolated from refined soya bean oil by chromatography on silica gel. Additional fractionation by preparative gel permeation chromatography yielded a product containing 92% of dimeric triglycerides. By this for the first time genuine dimeric triglycerides have been available for animal feeding experiments at a very high concentration which otherwise occur in refined soya bean oils only in very low amounts. The acute toxicity test with mice, in which the 92% concentrate was fed, did not show any symptoms of toxicity with all doses applied. The acute LD₅₀ (24 hours and 7 days) was higher than 20 ml/kg. To test the chronical toxicity and metabolism the product with 20% dimeric triglycerides was added at 15% (w/w) to the diet and fed to mice over 12 months. A control group of test animals received a diet with 15% (w/w) refined soya bean oil. During the experiment a. o. clinical symptoms, behavioural disorders, gain in weight, uptake of feed and water, feed efficiency and mortality have been evaluated. Histological investigations as well as a reproduction study were performed. In all these investigations no differences between the animals of the control and test groups could be found. Fat analytical investigations revealed that the dimeric triglycerides are saponified in the gastro-intestinal tract and that a high percentage of dimeric fatty acids is excreted with the faeces. Liquids isolated from the adipose tissue, the kidneys and brain did not show any difference between the animals of the control and test group.     

Stereospezifische Analyse von Triacylglycerinen mit selten vorkommenden Fettsäuren

Stereospecific Analysis of Triacylglycerides with Rarely Occuring Fatty Acids The glyceride structure of seed oils which contain each a rarely occurring fatty acid at a higher amount, is investigated. Seeds of 12 plants from three families are available. Besides the stereospecific analysis of the triglycerides by lipases of pancreas and of various mushrooms partial deacylation with ethylmagnesium bromide are carried out. By means of reverse phase HPLC a separation in individual triacylglycerides is performed; even a separation of such glycerides takes place which only differ in one isomeric fatty acid. The distribution of the fatty acids on the sn-positions of glycerol does not follow in all plants the hypothesis of C. D. Evans.     

Reinste Fettsäuren durch neuartige Fraktionierverfahren mit ACV-Hochleistungskolonnen I

Pure Fatty Acids by Novel Process of Fractionation Using High Efficiency ACV Columns A survey on the nature, properties and amounts of natural and synthetic raw materials available for the fatty acids is followed by a comprehensive discussion of conditions employed for preparation of pure individual fatty acids from these mixtures. It is shown that starting from mixtures of fatty acids, their esters as well as alcohols which are available for large scale operations, chemically pure components having purity of over 99% can be obtained. For this purpose, umbrella-type bubble and multi-flow sieve tray constructions developed by ACV, were found to be efficient as separating units with low pressure drop. Taking the examples of processing of coconut and cottonseed oil fatty acids it is shown as to how by an appropriate combination of various columns and evaporators practically any desired purities can be obtained; thereby byproducts and residual components that are present in small amounts do not accumulate. The ACV systems described here are superior to those plants which are operated with stripping steam, especially with respect to low utility costs. These are DM 12.50/t for straight distillate, DM 35.29/t for individual coconut fatty acid fractions with purities above 99.9% and DM 30.96/t for a 99% C₁₈-fraction obtained from cottonseed fatty acids.     

Untersuchungen über die Struktur dimerer Fettsäuren V: Thermische und peroxidkatalysierte Dimerisierung von Linolensäure-methylester

Investigations on the Structure of Dimeric Fatty Acids V: Thermal and Peroxide-Catalyzed Dimerisation of Methyl Linolenate By heating methyl linolenate at 280° C in high vacuum 26% dimers resulted besides 2% hydrocarbons, 24% methyl esters of monocarboxylic acids, 46% polymers and methyl esters of dicarboxylic acids. The dimers comprise of mainly penta-, tetra-, tri- and bicyclic types. Dehydro dimers obtained by catalytic action of di-tert-butyl peroxide on methyl linolenate at 140° C were mainly of the acyclic type containing 6 double bonds.     

Eigenschaften verzweigter Fettsäuren

Properties of Branched Fatty Acids Physical and chemical properties of branched fatty acids and hydroxy fatty acids were determined and compared with those of n-fatty acids.     

Regioselektive C-H-Funktionalisierung von Fettsäuren und Fettsäuremethylestern

Regioselective C-H-Functionalization of Fatty Acids and their Methyl Esters Fatty acids and thier methyl esters can be chlorinated preferentially at the terminal methylene groups with N-alkylchloroamines in sulfuric acid. With capric acid and its methyl ester the optimal reaction conditions for the selective chlorination were elaborated and then transferred to longer fatty acids up to stearic acid. The influence of the solvent, the temperature and the nature of different chlorinating reagents on the selectivity was studies. The capillary GC/MS-analysis of the isomeric chlorinated fatty acids is described.     

Untersuchungen zur Aktivitätsveränderung eines mit Fettsäuren passivierten Katalysators

Investigations Concerning Changes in Activity of a Catalyst Passivated by Fatty Acids The possibility of passivating the Ni-catalyst by fatty acids on kieselguhr at a temperature of 75°C in an unmixed system during 168 hours was tested. The activity of the catalyst depended on the degree of reduction, the specific surface and the time of passivation. During passivation a correlation of the system Ni-NiO with the fatty acids by formation of Ni-soaps (max. 27% p. weight) took place.     

Das Verhalten von Ni-Katalysatoren bei der Passivierung mit freien Fettsäuren

Behaviour of Ni-Catalysts in Passivation by Free Fatty Acids In the submitted work the possibilities were checked to produce Ni-catalyst on a carrier passivated by free fatty acids. It was demonstrated that the reactivity of the catalyst system Ni-NiO is much more higher with respect to the formation of Ni-soaps than with NiO or Ni alone. The reaction is divided in the three following phases: starting phase, decomposition phase and the phase of continuous growth. The third phase follows the kinetics of zero order. The activity of the Ni-catalyst passivated by fatty acids depends on the degree of reduction.     

Quantitative Papier-Chromatographie der Fettsäuren

Systematic Quantitative Analysis of Natural Waxes with the Help of Ion-Exchange, Column and Thin-Layer Chromatography A method was developed for the quantitative separation of natural waxes into substance classes. The hydrocarbons were separated by the adsorption chromatography on silica gel/CS₂ column and the separation of acids from alcohols was achieved on a two-phase ion-exchange column after saponification. The isolation of the individual homologues (C₁₆? C₃₂) from the alcohol and acid mixtures was carried out with the help of reversed phase column chromatography by stepwise increase in temperature and acetic acid concentration.     

Zur Chemie der cyclischen Fettsäuren

Cyclic Fatty Acids Following a review, the most important processes for preparing monomeric cyclic fatty acids are dealt with. In the alkali cyclization of triunsaturated fatty acids, formation of cyclizable isomers having a central cis-structure takes place preferentially compared to thermal ring closure. Compared to conjugated or isolated structure, cis/trans configuration of double bonds have stronger impact on distribution of isomers in cyclic acids formed. Isolated unsaturated trienoic fatty acids yield also bicyclic compounds having indanyl structure besides monocyclic compounds. Heterogeneous catalytic cyclization with Pd/C or Ni favours more extensive displacement of double bonds and disproportionation leading to formation of aromatics besides monoenoic and saturated fatty acids.     

Untersuchungen über die Struktur dimerer Fettsäuren III: Zur Frage der Diels-Alder-Reaktion bei der thermischen Polymerisation von Linolsäure-methylester

Investigations on the Structure of Dimeric Fatty Acids, Part III: Diels-Alder-Reaction in the Thermal Polymerization of Methyl Linoleate To start with, the literature involving the role of Diels-Alder-reaction in the thermal polymerization of methyl linoleate is summarized. It is shown experimentally that methyl-9^c,12^c-linoleate undergoes conjugation only in the presence of free radicals. In this reaction, radicals with conjugated diene systems are formed, which, in contrast to molecules with conjugated diene systems, do not enter into Diels-Alder-reaction. The conjugated radicals get stabilized at 135°C under the formation of acyclic dimers.